Image recording devices, such as laser printers, use a replaceable cartridge containing a recording material to record an image on a recording medium.
Electrostatic or laser printers form an image on a recording medium by transferring toner particles onto the medium. Typically, a recording drum is charged and a latent image is formed on the drum by a laser. The latent image is developed on the drum by developer or toner particles and this image is transferred directly or indirectly onto a recording medium. In color printers multiple cartridges are provided to transfer color images.
A print cartridge often includes a memory device. This memory device may be loaded with information indicative of the cartridge parameters. When the printer detects that a new cartridge has been installed, the printer reads the information from the memory device. This information can be used to calibrate the operation of the printing device based upon the cartridge parameters. Often, the memory device includes information related to the cartridge capacity. The printer may read the cartridge capacity and print a status page telling the user information about the cartridge. The status page may include information such as manufacture date, cartridge type, and estimated page count for the cartridge.
The information stored in the memory may also be used to monitor the print life of the cartridge. One method of monitoring usage of a print cartridge is to count the amount of printing that is performed. In an electrostatic printer a counter may count the number of lines or pages printed by each cartridge. Each of the numbers counted is then processed as a count signal and the printer sends each of the count signals to the appropriate cartridge. The cartridge contains a memory that stores an initial value indicative the amount of printing agent contained in the cartridge. The printer uses the initial value and the number of pages or lines printed to determine a remaining life of the cartridge. When the cartridge gets to a low level, the printer may warn an operator to replace the cartridge and eventually prevent the cartridge from being used.
A used print cartridge contains many parts that have a useful life after the first use. It is desirable to refill or remanufacture these used print cartridges. This provides a less expensive alternative than purchasing new print cartridges, and reduces waste. When refilling a print cartridge, it is advantageous to provide a cartridge that has an increased print life. In an ink jet printer, the print life can be increased by adding more ink than cartridge was originally filled with or by using ink that has a higher print efficiency. In a laser printer, the print life can be extended by filling the cartridge with additional toner or by using toner that has an increased print efficiency.
When it is desired to provide a higher yield cartridge, it is necessary to change the initial value stored in the memory. If a cartridge has the capacity to record and increased number of pages and the initial value does not reflect this increased capacity, the printer may prevent the cartridge from realizing its full print life. Also, if the information stored in the memory does indicate an increased print capacity, the status page printed will not reflect the proper page count.
Therefore, on object of the invention is to provide a high yield print cartridge that displays the proper information on the status page and that prints until the cartridge is empty, or almost empty, of recording material.